The present invention relates generally to airbags used for lifting vehicles and more particularly to an airbag adopted for elevating of the body of an aircraft in order to facilitate an emergency egress of passengers from the aircraft.
It is essential on any transport aircraft that, in the event of a ground emergency, the crew and passengers are able to exit the aircraft in a very short period of time. The Federal Aviation Administration (FM) requires the complete evacuation of a commercial transport within specific time limits. The problem of emergency egress of an aircraft is compounded when, due to a malfunction of the landing gear, or the aircraft fuselage coming to rest in an abnormal position after an emergency landing, certain emergency exit doors cannot be effectively utilized because of the proximity of the fuselage to the ground. This potential problem is specifically relevant to aircraft utilizing a rear ventral emergency exit, such as aircraft with a blended wing-body design.
In a blended wing-body aircraft, emergency exit doors on the rear underside of the aircraft fuselage are designed to allow emergency egress of passengers and crew when the aircraft is supported above the ground by the landing gear. If the landing gear does not deploy fully or is damaged or is otherwise ineffective in elevating the aircraft fuselage, the ventral exit doors may be unusable because of the insufficient ground clearance of the fuselage relative to the ground. This is especially significant if the ventral exit doors open outward and are blocked from opening due to the proximity of the ground. However, even if opening the ventral exit doors is not an issue, clearance is needed to permit deployment of emergency exit devices such as slides or simply allow for the physical movement of persons through the ventral exit doorways. This situation can be resolved if a system can be provided to raise the aircraft to a level above the ground where the exit doors can be effectively utilized to allow expedient egress of passengers and crew.
Therefore, there is a need for a system that will temporarily elevate a fuselage of an aircraft off the landing surface to permit rapid evacuation of crew and passengers through the emergency exit doors of the aircraft in the event of a ground emergency.
A specific object of the invention is to provide a system that can provide clearance for effectively utilizing rear ventral exit doors by elevating the fuselage of the aircraft to allow adequate ground clearance to open and exit the rear ventral exit doors in the event of an emergency landing situation where the landing gear has not adequately deployed to elevate the fuselage of the aircraft.
For blended wing-body aircraft, it is another object of the invention to provide a system for allowing access to emergency exits and allowing passengers egress through exit doors in an expeditious manner after an emergency landing. It is yet another object of the invention to provide a system for blended wing-body aircraft that will allow for the installation of emergency exits near or along the lower surface and aft of the aircraft, without the risk of such exits being unusable due to a landing gear malfunction, damage or other ineffectiveness in elevating the aircraft upon landing.
The present invention is directed to an emergency airbag system for use with an aircraft. The system provides an airbag disposed within the aircraft that when activated deploys the airbag external to the fuselage of the aircraft for the purpose of elevating the fuselage of the aircraft. This ensures that emergency exit doors on the underside of fuselage have sufficient clearance to be utilized, despite the failure of the landing gear of the aircraft adequately elevate the aircraft, creating a situation where there would otherwise be insufficient clearance to use the emergency exit doors. The airbag is advantageously stowed within the aircraft to reduce aerodynamic drag caused by other systems designed to elevate the aft fuselage of an aircraft.
The invention makes use of an activation system which is connected to the airbag for the purpose of deploying the airbag. The activation system, in one preferred embodiment, includes a chemical cartridge that burns or rapidly changes form from a solid to a gas when ignited by an electrical signal. In an alternative embodiment, the activation system includes a fluid reservoir for storing a pressurized fluid that can be released into the airbag causing it to expand.
The activation system includes a switching system to prevent the deployment of the airbag in certain situations such as when the aircraft is in flight or when the landing gear is adequately extended. The switching system controls the application of power from an electrical power source that is also connected to the gas generating charge intended for deploying the airbag.
In operation, a flight attendant or crew member of the aircraft determines the necessity of deployment of the airbag system. Once the decision is made to deploy the system, the system is deployed by initiating the activation mechanism that inflates the airbags. Once the airbags are inflated, it provides clearance at the rear (i.e., aft) area of the aircraft by lifting the aft end of the fuselage a sufficient height off of the ground to allow the utilization of an emergency exit door for egress of passengers and crew members.
The aircraft emergency airbag system of the present invention may also be deployed in a manner to prevent the sinking of an aircraft in an emergency water landing (ditching) incident. Inflation of one or more of the airbags after such an incident would significantly improve the survivability of the crew and passengers by keeping the cabin above the water level and preventing the aircraft from sinking.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.